12. f3d4 Black is full of weaknesses and the king is still in the middle of the board. The f5-pawn is attacked and the knight can also go to e6. 12... d5c4 This makes things even worse, but it's hard to recommend anything. 13. d4e6  13... d8c8 Black's position is sad and I guess even die-hard Carlsen fans didn't expect a turnaround at this point. 14. f2f3 Many roads lead to Rome.